1. Field of the Invention
This invention concerns a novel phosphoric ester and, more specifically, it relates to a phosphoric ester represented by the following general formula (I): ##STR3## wherein R.sub.1 represents a linear or branched alkyl or alkenyl group having 1 to 36 carbon atoms, or a phenyl group substituted with a linear or branched alkyl group having 1 to 15 carbon atoms, R.sub.2 represents an alkylene group having 2 to 3 carbon atoms, R.sub.3, R.sub.4 and R.sub.5 individually represent a hydrogen atom or a linear or branched alkyl group having 1 to 36 carbon atoms providing that any one of R.sub.3, R.sub.4 and R.sub.5 has 5 or more carbon atoms, and n is a number from 0 to 30.
2. Description of the Prior Art
Phosphoric esters have been utilized in various fields as detergents, fiber processing agents, emulsifiers, rust inhibitors, liquid ion exchangers or pharmaceuticals.
For the detergents, alkyl sulfates, alkylbenzene sulfonates, .alpha.-olefin sulfonates and the likes have hitherto been used. However, since many of these surface active agents roughen the skin, it has been demanded to provide such detergents causing less irritations to the skin. Recently, phosphoric monoester salts have been used as less stimulating surface active agents.
The living body contains various phosphate type surfactants having quaternary ammonium salts in one molecule and referred to as a phospholipid. Lecithin and phosphatidyl serine are typical examples of the phospholipid. These phospholipids are utilized in various fields because of their surface activity, emulsifying ability and physiological properties. In view of this, it is expected that those substances having structures similar to the phospholipids are less stimulative to the living body as compared with the aforementioned phosphoric acid monoester salts, and syntheses of various phospholipid-like substances have been conducted. However, since the syntheses often require multi-step reactions, yields for most of aimed products are often low (E. Baer, et al., Journal of the American Chemical Society, 72, 942 (1950)).
Under the above circumstances, several of the present inventors succeeded in obtaining a novel compound having a quaternary ammonium salt in one molecule represented by the following formula in a simple procedure: ##STR4## wherein R.sub.6 represents a linear or branched saturated or unsaturated hydrocarbon group which may possibly be substituted and having from 8 to 32 carbon atoms, R.sub.8, R.sub.9 and R.sub.10, which may be different or identical with other, represent individually a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, R.sub.7 represents an alkylene group having 2 to 3 carbon atoms and m represents an integer from 0 to 50 (Japanese Patent Application No. 39042/1984). More particularly, they found that the compound can be produced easily by reacting a monoalkali metal salt of a monoalkylphosphoric acid represented by the formula (III) with a glycidyltrialkyl ammonium salt represented by the formula (IV) in accordance with the following reaction scheme and that a representative compound, dodecyl-2-hydroxy-3-N,N,N-trimethylammoniopropyl phosphate (R.sub.6 =C.sub.12 H.sub.25, R.sub.8 =R.sub.9 =R.sub.10 =CH.sub.3, and m=0 in the compound (II)) has an excellent deterging effect and extremely low stimulation to the living body. ##STR5## wherein M.sub.1 represents an alkali metal, X.sub.1 represents an anion and R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and m have the same meanings as described above.
However, among the glycidyltrialkyl ammonium salts, only glycidyltrimethyl ammonium chloride is industrially available at present and it has been difficult to industrially obtain those compounds having various alkyl ammonio groups.